51EasyUI 树形菜单- 创建异步树形菜单

<ul id="tt" class="easyui-tree"
            url="tree2_getdata.php">
    </ul>

$id = isset($_POST['id']) ? intval($_POST['id']) : 0;
    include 'conn.php';
    $result = array();
    $rs = mysql_query("select * from nodes where parentId=$id");
    while($row = mysql_fetch_array($rs)){
        $node = array();
        $node['id'] = $row['id'];
        $node['text'] = $row['name'];
        $node['state'] = has_child($row['id']) ? 'closed' : 'open';
        array_push($result,$node);
    }
    echo json_encode($result);
    function has_child($id){
        $rs = mysql_query("select count(*) from nodes where parentId=$id");
        $row = mysql_fetch_array($rs);
        return $row[0] > 0 ? true : false;
    }